Biomaterial Database

Diagnosis of Krabbe disease by use of a natural substrate. 2006

John W Callahan, and Marie-Anne Skomorowski

Genetic-Metabolic Laboratory, Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Canada.

This chapter describes in detail a practical procedure for the preparation of radiolabeled galactocerebroside and its use in the assay of galactocerebrosidase (GalCase), the enzyme deficient in globoid cell leukodystrophy (Krabbe disease). The reference range for leukocytes and fibroblasts is 0.9-4.4 and 8-36 nmoles substrate hydrolyzed per hour per milligram of protein, respectively. Because of its low abundance this enzyme is difficult to assay in certain situations, such as prenatal diagnosis by chorionic villus sampling. To obviate this a modified assay is used where only the radiolabeled substrate is included in the incubation. This provides a clear separation between affected samples and unaffected controls. The methods detailed here should be reproducible in any laboratory.

UI	MeSH Term	Description	Entries
D007965	Leukodystrophy, Globoid Cell	An autosomal recessive metabolic disorder caused by a deficiency of GALACTOSYLCERAMIDASE leading to intralysosomal accumulation of galactolipids such as GALACTOSYLCERAMIDES and PSYCHOSINE. It is characterized by demyelination associated with large multinucleated globoid cells, predominantly involving the white matter of the central nervous system. The loss of MYELIN disrupts normal conduction of nerve impulses.	Diffuse Globoid Body Sclerosis,Galactosylceramidase Deficiency Disease,Krabbe Disease,Classic Globoid Cell Leukodystrophy,Early-Onset Globoid Cell Leukodystrophy,GALC Deficiency,Galactocerebrosidase Deficiency,Galactosylceramide Lipidosis,Galactosylceramide beta-Galactosidase Deficiency,Galactosylceramide-beta-Galactosidase Deficiency Disease,Galactosylcerebrosidase Deficiency,Galactosylsphingosine Lipidosis,Globoid Body Sclerosis, Diffuse,Globoid Cell Leukodystrophy,Globoid Cell Leukoencephalopathy,Globoid Leukodystrophy,Infantile Globoid Cell Leukodystrophy,Krabbe Leukodystrophy,Krabbe's Disease,Krabbe's Leukodystrophy,Late-Onset Globoid Cell Leukodystrophy,Leukodystrophy, Globoid Cell, Classic,Leukodystrophy, Globoid Cell, Early-Onset,Leukodystrophy, Globoid Cell, Infantile,Leukodystrophy, Globoid Cell, Late-Onset,Psychosine Lipidosis,Cell Leukodystrophies, Globoid,Cell Leukodystrophy, Globoid,Cell Leukoencephalopathies, Globoid,Cell Leukoencephalopathy, Globoid,Deficiencies, GALC,Deficiencies, Galactocerebrosidase,Deficiencies, Galactosylceramide beta-Galactosidase,Deficiency Disease, Galactosylceramidase,Deficiency Disease, Galactosylceramide-beta-Galactosidase,Deficiency Diseases, Galactosylceramidase,Deficiency Diseases, Galactosylceramide-beta-Galactosidase,Deficiency, GALC,Deficiency, Galactocerebrosidase,Deficiency, Galactosylceramide beta-Galactosidase,Disease, Galactosylceramidase Deficiency,Disease, Galactosylceramide-beta-Galactosidase Deficiency,Diseases, Galactosylceramidase Deficiency,Diseases, Galactosylceramide-beta-Galactosidase Deficiency,Early Onset Globoid Cell Leukodystrophy,GALC Deficiencies,Galactocerebrosidase Deficiencies,Galactosylceramidase Deficiency Diseases,Galactosylceramide beta Galactosidase Deficiency,Galactosylceramide beta Galactosidase Deficiency Disease,Galactosylceramide beta-Galactosidase Deficiencies,Galactosylceramide-beta-Galactosidase Deficiency Diseases,Globoid Cell Leukodystrophies,Globoid Cell Leukoencephalopathies,Globoid Leukodystrophies,Krabbes Disease,Krabbes Leukodystrophy,Late Onset Globoid Cell Leukodystrophy,Leukodystrophies, Globoid,Leukodystrophies, Globoid Cell,Leukodystrophy, Globoid,Leukodystrophy, Krabbe,Leukodystrophy, Krabbe's,Leukoencephalopathies, Globoid Cell,Leukoencephalopathy, Globoid Cell,beta-Galactosidase Deficiencies, Galactosylceramide,beta-Galactosidase Deficiency, Galactosylceramide
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011296	Prenatal Diagnosis	Determination of the nature of a pathological condition or disease in the postimplantation EMBRYO; FETUS; or pregnant female before birth.	Diagnosis, Prenatal,Fetal Diagnosis,Fetal Imaging,Fetal Screening,Intrauterine Diagnosis,Antenatal Diagnosis,Antenatal Screening,Diagnosis, Antenatal,Diagnosis, Intrauterine,Prenatal Screening,Antenatal Diagnoses,Antenatal Screenings,Diagnosis, Fetal,Fetal Diagnoses,Fetal Imagings,Fetal Screenings,Imaging, Fetal,Intrauterine Diagnoses,Prenatal Diagnoses,Prenatal Screenings,Screening, Antenatal,Screening, Fetal,Screening, Prenatal
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D005260	Female		Females
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D005692	Galactose Oxidase	An enzyme that oxidizes galactose in the presence of molecular oxygen to D-galacto-hexodialdose. It is a copper protein. EC 1.1.3.9.	Oxidase, Galactose
D005698	Galactosylceramidase	An enzyme that hydrolyzes galactose from ceramide monohexosides. Deficiency of this enzyme may cause globoid cell leukodystrophy (LEUKODYSTROPHY, GLOBOID CELL). EC 3.2.1.46.	Galactocerebrosidase,Galactosylceramide Galactosidase,Galactosylceramide beta-Galactosidase,Galactosylcerebroside beta-Galactosidase,Galactosidase, Galactosylceramide,beta-Galactosidase, Galactosylceramide,beta-Galactosidase, Galactosylcerebroside
D005699	Galactosylceramides	Cerebrosides which contain as their polar head group a galactose moiety bound in glycosidic linkage to the hydroxyl group of ceramide. Their accumulation in tissue, due to a defect in beta-galactosidase, is the cause of galactosylceramide lipidosis or globoid cell leukodystrophy.	Galactocerebrosides,Galactosyl Ceramide,Galactosyl Ceramides,Galactosylceramide,Ceramide, Galactosyl,Ceramides, Galactosyl